Issue with multiple tabs, or staying in the same tab when clicking on a ling in email

For a few days now this thing with the tabs is driving me crazy. When I click on some link a new tab opens, then I click on another link another tab opens. Following some instructions I went to about:config where I was asked to look for neww, then change the default from 3 to 1. That solved the issue with opening multiple tabs, but now when in gmail and I click on a link it remains in the same page and I have to keep getting back to gmail to continue reading my emails. That was not the behavior before. When I clicked on a link in my email I was taking to a new tab. Which was OK. But then lately every time I click on something it keeps opening new tabs. This is so annoying. What can I do to go back to the settings I had a week or more ago. This is FRUSTRATING!!!! Thanks so much for your help on this matter. Ana In email when I click on a link